Latex physiological parameters are good indicators of rubber production and have been shown to be invaluable in the selection of new rubber clones, development of latex harvesting technology, and prediction of tapping panel dryness. This study was aimed to investigate the effect of 2.5% Mortex; an oil-based stimulant, and 2.5% ethephon on latex physiological parameters as well as tree productivity of RRIM 3001, during high (HY), moderate (MY) and low (LY) yielding periods. Latex pH, sucrose, proline, thiol contents, plugging index, tapping panel dryness, dry rubber content and tree productivity were analysed in both stimulated and control trees. Sucrose, which is the primary metabolite that is required for latex regeneration was reduced by 22% and 33% during the MY and HY periods, respectively. Thiol, that has been associated with rubber particle membrane integrity, increased during LY and HY periods, respectively. Thiol, that has been associated with rubber particle membrane integrity, increased during LY and HY periods. On the other hand, both Mortex and ethephon stimulation resulted in a comparable reduction in plugging index after one and three days of stimulation, when compared to the control. Stimulation treatments have different impacts on seasonal variation of physiological parameters. The effects of Mortex and ethephon on tree productivity, dry rubber content and tapping panel dryness were also discussed. Upon completion, this study may serve as a model for evaluating latex stimulant products in the market.